1. Field of the Invention
The invention relates to a trailer hitch assembly for connecting a gooseneck trailer to a pickup truck, and in particular to a readily removable friction engaging hitch assembly that is adapted to the box of a pickup truck without causing damage.
2. Discussion of the Technical Problems
The use of "gooseneck" or "fifth wheel" trailers has become quite common. It has been found that by having the pivotal hitch point of a trailer over the rear axle of the towing vehicle that far greater loads can be transported safely than was possible with conventional trailers having the hitch point behind the rear axle such as on the rear frame or bumper. Such a trailer is also more stable in a crosswind, has a better turning radius than a conventional trailer and "tracks" or trails much better even with the increased loads.
With expanded agriculural, industrial and recreational use of gooseneck and fifth wheel trailers, it has been discovered that the ideal towing vehicle is the pickup truck. A pickup truck allows convenient access to a hitch point over the rear axle and is of a more heavy-duty construction than a conventional automobile.
In order to connect a fifth wheel trailer to a pickup truck numerous hitches have been developed. The true "fifth wheel" hitch approximates a fifth wheel hitch for a semi-trailer commercial truck and is quite complicated. It uses a flat plate "wheel" which must be capable of tilting and have a wedge connection slot for coupling. Since the loads towed by a pickup truck are limited, other lighter and simpler fifth wheel hitches have been developed specifically for pickup trucks. One such hitch is found in U.S. Pat. No. 4,327,934 to Karnes. Others are described in U.S. Pat. No. 3,759,545 to McKethan and U.S. Pat. No. 3,811,706 to Tucker et al.
The gooseneck trailer hitch is also in common use and it is a natural for pickup trucks. It has most of the advantages of the fifth wheel trailer but is generally lighter, considerably simpler and differs from the fifth wheel hitch in that it uses a standard ball and socket. The ball generally is placed in the bed of the pickup truck and the socket is an intregal part of the trailer's vertically desending tongue. U.S. Pat. No. 3,790,188 to Johannes describes one such hitch as does U.S. Pat. No. 4,077,650 to Leach Jr., U.S. Pat. No. 3,788,673 to Gloege and U.S. Pat. No. 3,733,089 to Goecke et al.
Regardless of the type of hitch employed, the attachment of the hitch to the pickup truck remains a problem if the full utility of the pickup truck is to be enjoyed. Once a hitch is bolted or welded to the bed of one's pickup truck it usually remains there. The hitch interfers with normal loading.
While a relatively flat portion of a hitch may seem to not interfer with normal loading, such is not the case if one wants to use the pickup box for hauling grain, sand, or other loose material. U.S. Pat. No. 4,183,548 to Schneckloth describes a hitch that leaves a bolted relatively flat plate in the bed of the disconnected pickup.
In order to fully utilize the advantages of the gooseneck or fifth wheel trailer and a pickup truck it is necessary to be able to fully remove the pickup attachment portion of the hitch when not in use. The removal should be easily accomplished without the necessity of using tools. U.S. Pat. No. 4,088,339 to Sagebiel provides a removable hitch assembly that uses pickup mounted retaining brackets and a pair of locking pins. The pickup bed must be modified to use the Sagebiel hitch assembly.
The prior art fails to disclose a readily removable trailer hitch assembly that does not modify the pickup truck bed or require drilling bolting or welding. Of course, a modified pickup bed or box would tend to reduce the resale value of the truck and in that manner deprive the owner of its full utility. It also makes such a hitch difficult to switch from one truck to another.
Accordingly, a need exists for a trailer hitch assembly that is fully removable when not in use, is easily adapted to diferent pickup trucks, does not require modification of the truck bed and can be installed and removed without the use of tools. The instant invention is directed to these and other needs as will become apparent upon a careful reading of this specification.